As both a Hue and HS110 smartplug user, I’ll give my perspective. The beauty of Hue and smartplugs is that they result in more known devices in your house, and less power ending up in either Always On or Other categories. The HS110 also helps with learning the device it is attached to, but not device on outlet strips, since the smartplug supplies Sense with ‘ground truth’ for that specific device. ‘Ground truth’ is a key ingredient in the machine learning training process.
I don’t think having things identified via smartplug or Hue helps focus Sense on ‘other things’ within your house. It’s not like the Sense algorithms can subtract off found devices from the waveform. Training is more about Sense learning how to focus in on very selective aspects of the incoming waveforms, not ‘elimination’. But you do benefit from others who use smartplugs and supply ground truth for devices you have in your house, that you may or may not have used a smartplug on.